Acute anterior shoulder dislocation is an injury where the top end of the upper arm bone is pushed out of the joint socket in a forward direction. Afterwards, the shoulder is less stable and prone to redislocation, especially in active young adults. Initial treatment involves putting the joint back; this is called 'reduction'. 'Closed reduction' refers to cases where this is done without surgery. Subsequent treatment is often conservative (non-surgical), and generally involves placing the injured arm in a sling or other immobilising device followed by exercises.
After a comprehensive search for randomised controlled trials that compared different methods of conservative management for these injuries, we included only one small trial. This compared immobilisation of the arm in either external rotation (where the arm was orientated outwards with the forearm away from the chest) or internal rotation (the usual sling position where the arm rests against the chest) following closed reduction. Preliminary results for 40 adults showed no statistically significant difference between the two groups in terms of previously active athletes' return to pre-injury sports, nor in redislocation or shoulder instability. Similar numbers of participants in each of the two groups removed their immobiliser before one week had passed. This multicentre trial was flawed by its use of inadequate methods of allocating patients to the trial intervention groups and its inadequate assessment of outcome.
In conclusion, there is a lack of evidence from randomised controlled trials to inform the choices for conservative management following closed reduction of traumatic anterior dislocation of the shoulder.